Ag and Cu loaded on TiO<Subscript>2</Subscript>/graphite as a catalyst for <Emphasis Type="Italic">Escherichia coli</Emphasis>-contaminated water disinfection

TiO₂ film was synthesized by means of the chemical bath deposition (CBD) method from TiCl₄ as a precursor and surfactant cetyl trimethyl ammonium bromide (CTAB) as a linking and assembling agent of the titanium hydroxide network on a graphite substrate. Ag and Cu were loaded on the TiO₂ film by means of electrodeposition at various applied currents. Photoelectrochemical testing on the composite of Ag-TiO₂/G and Cu-TiO₂/G was used to define the composite for Escherichia coli-contaminated water disinfection. Disinfection efficiency and the rate of disinfection of E. coli-contaminated water with Ag-TiO₂/G as a catalyst was higher than that observed for Cu-TiO₂/G in all disinfection methods including photocatalysis (PC), electrocatalysis (EC), and photoelectrocatalysis (PEC). The highest rate constant was achieved by the PEC method using Ag-TiO₂/G, k was 6.49 × 10⁻² CFU mL⁻¹ min⁻¹. Effective disinfection times of 24 h (EDT₂₄) and 48 h (EDT₄₈) were achieved in all methods except the EC method using Cu-TiO₂/G.     

Effect of styrene–acrylonitrile content on 0.5?M NaI/0.05?M I2 liquid electrolyte encapsulation for dye-sensitized solar cells

The effect of a gel polymer electrolyte (GPE) as the redox electrolyte used in dye-sensitized solar cells was studied. A GPE solution consisting of 0.5?M sodium iodide, 0.05?M iodine, and ethylene carbonate/propylene carbonate (1:1 w/w) binary solvents was mixed with increasing amounts of styrene–acrylonitrile (SAN). Bulk conductivity measurements show a decreasing trend from 4.54 to 0.83×10^?3?S?cm^?1 with increasing SAN content. The GPE exhibits Newtonian-like behavior and its viscosity increases from 0.041 to 1.093?Pa?s with increasing SAN content. A balance between conductivity (1.3?×?10^?3?S?cm^?1) and viscosity (1.4?Pa?s) is observed at 19?wt.% SAN. Fourier transform infrared spectroscopy detects elevated ring torsion at 706?cm^?1 upon the addition of SAN into the liquid electrolyte. This indicates that SAN does not bond with the liquid electrolyte. Finally, the potential stability window of 19?wt.% SAN, which ranges from ?1.68 to 1.38?V, proves its applicability in solar cells.     

Studies on coordination chemistry of a nitrogen–sulfur donor ligand with lighter and heavier metal ions and biological activities of its complexes

Complexes of S-benzyldithiocarbazate (SBDTC) with lighter and heavier metals, viz., Cr^III, Fe^III, Sb^III, Zr^IV, Th^IV and U^VI have been prepared and characterized by elemental analyses, conductivity measurements, and spectral studies. The complexes: [Cr(SBDTCA)₃],^** [Fe(SBDTCA)₃], [Sb(SBDTCA)₃], [Sb(SBDTCA)₂Cl · H₂O], [Zr(O)(SBDTCA)₂ · H₂O], [Th(SBDTCA)(NO₃)₃ · H₂O)], and [U(O)₂(SBDTCA)₂] were all prepared in alkaline media. They were all hexa-coordinated with bidentate, uninegative chelation of the ligand. [Fe(SBDTCA)₃], [Sb(SBDTCA)₃] and [Sb(SBDTCA)₂Cl · H₂O] were strongly effective against bacteria giving clear inhibition zones with Pseudomonas aeruginosa and Bacillus cereus. The compounds showed poor antifungal activity. The antimony complexes were strongly cytotoxic against leukemic cells with CD₅₀ values of 3.2–6.7 g cm^–3 as compared to the CD₅₀ value of 14.5 g cm^–3 of the free SbCl₃ molecule.     

Electrochemical impedance study of lithium-ion insertion into rice husk carbon

Electrochemical impedance spectroscopy (EIS) was employed to study electrochemical behaviors during Li-ion insertion into rice husk carbon. The impedance spectra consist of two depressed semicircles in the high and middle range frequency and an incline line at low frequency. The impedance spectra, obtained in the potential range 2.0 to 0.005 V were analyzed with an equivalent circuit model. Kinetic parameters such as the charge-transfer resistance and surface film resistance were evaluated and discussed. Paper presented at the International Conference on Solid State Science and Technology 2006, Kuala Terengganu, Malaysia, September 4–6, 2006.     

Synthesis,structural characterization and cytotoxic activity of organotin derivatives of indomethacin

The synthesis, characterization and cytotoxic properties in vitro of tri‐n‐butyltin 1‐(4‐chlorobenzoyl)‐5‐methoxy‐2‐methyl‐1H‐indole‐3‐acetate ( 1 ), tri‐phenyltin 1‐(4‐chlorobenzoyl)‐5‐methoxy‐2‐methyl‐1H‐indole‐3‐acetate ( 2 ), tetra‐n‐butyltin[bis‐1‐(4‐chlorobenzoyl)‐5‐methoxy‐2‐methyl‐1H‐indole‐3‐acetato]distannoxane ( 3 ) and di‐n‐butyltin bis‐1‐(4‐chlorobenzoyl)‐5‐methoxy‐2‐methyl‐1H‐indole‐3‐acetate ( 4 ) are described. These compounds have been characterized by ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy in solution and ¹¹⁹Sn NMR in the solid state, infrared spectroscopy, elemental analysis and X‐ray diffraction for compound 1 . The growth inhibition effects of compounds 1–4 against the lung adenocarcinoma cell line SK‐LU‐1 as well as the cervical cancer cell line HeLa were determined. Compounds 1 and 2 exhibit cytotoxic activity, whereas compounds 3 and 4 are inactive. Copyright © 2008 John Wiley & Sons, Ltd.     

Proficiency testing for measurement of radon (222Rn) in drinking water

The Finnish Environment Institute in collaboration with the Radiation and nuclear safety authority (STUK) carried out the proficiency test for measurement of radon (²²²Rn) in water. Samples were taken from two drilled wells in November 2007. STUK has supplied the regional laboratories with RADEK MKGB-01 equipment based on gamma spectrometry. Two samples for this PT were taken from two drilled wells. Ground water moves irregularly in the process and cracks of the bedrock which is why each participant received an individual sample. Each participant’s sample was measured also by STUK using liquid scintillation counter (LSC) as the reference method in this proficiency test. In estimating laboratory performance the results that deviated less than ±10% from the value measured by STUK using LSC were regarded satisfactory. In total, 73% of the results in the analysis of the sample R1 and 82% in the analysis of the sample R2 deviated less than 10% from the values measured by STUK. The results reported by the participants were generally smaller than the results measured by STUK. The deviation between each participant’s result and the result measured by STUK with the LSC was ?7.4% (Sample R1) and ?6.2% (Sample R2). Due to the lack of certified reference materials and a reliable proficiency testing data, it is impossible to check the traceability of radon measurements by using the reference method (LSC) at this moment.     

One-pot synthesis of new 6-(alkylamine)dibenzo[c,e][1,2]oxaphosphinine-6-oxides

Several new 6-(alkylamine)-6H-dibenz[c,e][1,2]oxaphosphinine-6-oxides were prepared through a one-pot reaction, starting with 2-phenylphenol, phosphorus trichloride, and a Zn catalyst, to form 6-chloro-6H-dibenz[c,e][1,2]oxaphosphine. The alkylamine derivatives were subsequently prepared through a nucleophilic substitution reaction involving aliphatic amines and H₂O₂ oxidation under soft conditions. This method has the advantages that it is a one-pot synthesis, does not require an inert atmosphere, and involves in situ catalyst formation.